Roller cage for a profiling line

ABSTRACT

A roller cage for a profiling line, comprising: a support frame (F 1 ) that entirely delimits a non-operating area (A 1 ) which is external to the line; at least a motor ( 11 ) provided with a spindle ( 12 ) protruding externally of the non-operating area (A 1 ); at least a shaped roller ( 13,  mounted directly on the spindle ( 12 ) and arranged inside an operating area (B) of the line.

The present invention relates to a roller cage for a profiling line.

A profiling line substantially enables the production of longitudinally welded tubes, which are obtained by progressively bending a steel strip around a longitudinal axis, until bringing the longitudinal edges of the strip itself into contact. The longitudinal edges are welded together to obtain a tube. The tube is cut into sections of a pre-established length, according to known procedures. All production is carried out with a continuous process.

A profiling line substantially comprises a series of forming assemblies or roller cages, arranged in succession, each of which comprises at least two profiling rollers. The roller cages are configured to progressively bend the steel strip around a longitudinal axis, until lending it a tubular shape. The steel sheet is bent by passing the sheet itself between the rollers of the various cages, which, by contact, progressively deform the sheet. The strip slides continuously through the roller cages, becoming progressively deformed.

The roller cages available on the market according to the ordinary technology have two uprights or shoulders, with which the rollers of the cage are associated. The rollers of the cage are substantially positioned in the space comprised between the two shoulders. Positioned at one side of the cage, i.e. next to one of the two shoulders, is the cage motor assembly, comprising one or two motors, one or two reduction gearboxes and one or two Cardan joints for driving, in rotation, at least two rollers of the cage. The shoulder on the motor assembly side is normally fixed. The other shoulder of the cage, positioned on the opposite side of the motor assembly (operator side), is by contrast removable, both to enable access to the rollers and other components of the cage and allow them to be changed in the event of maintenance or in the event of a changeover in size of the product to be made. In order to change the equipment of the cage it is necessary to remove the mobile shoulder, take out the equipment to be replaced and install the equipment intended for the new production. Over time, quick changeover methods have been developed which involve the replacement, off line, of entire plates complete with cages. In this manner, an equipment changeover can take place off line during production downtimes.

The roller cages available on the market according to the ordinary technology have several drawbacks.

Firstly, it is necessary to double the supply of cages (double set of replacement plates), in order to always have one available in line and one off line. This implies an evident cost increase.

Moreover, it is necessary to have very ample spaces for positioning the cages outside the line and carrying out an equipment change.

A further drawback is represented by the danger of handling the cages mounted on the plate—which can reach an overall weight of 15-20 tonnes—with the use of overhead travelling cranes.

It should further be considered that present-day technology envisages for each cage, in the simplest case, a transmission of power to the drive rollers by means of flanges, Cardan shafts, one divider per cage, speed change gearbox and an electric motor. For example, a section of the line for calibrating the profile, provided with four cages, requires an electric motor, reduction gearbox, speed change gearbox, four dividers (splitters) (for distributing power to the four cages) and eight Cardan shafts (two per cage) with respective coupling flanges.

Alternatively, more advanced solutions envisage one electric motor per cage, one divider with gearbox per cage, and two shafts with respective coupling flanges per cage or even one reduction gearbox, with or without speed change, and one motor per individual axis.

Both solutions thus require a large amount of space on the motor assembly side, and moreover they have very low efficiency. Much of the energy delivered by the electric motors is used up, in fact, just to drive the transmission in rotation, with consequent losses due to the couplings between the reduction gears and the rolling of the bearings, because of the movement of the oil, etc.

The object of the present invention is to offer a roller cage for a profiling line which makes it possible to overcome the drawbacks of the roller cages available on the market according to the ordinary technology.

One advantage of the roller cage according to the present invention is that of being much more compact than the cages available on the market according to the ordinary technology.

Another advantage of the roller cage according to the present invention is that of considerably facilitating access to the shaped rollers, as well as all maintenance and/or replacement operations.

A further advantage of the roller cage according to the present invention is that of not requiring the use of reduction gearboxes or transmission members, which enables considerable cost savings and a substantial reduction in power losses.

Additional features and advantages of the present invention will become more apparent from the detailed description that follows of an embodiment of the invention in question, illustrated by way of non-limiting example in the appended figures, in which:

FIG. 1 shows a schematic partial cross-sectional view of a roller cage according to the present invention;

FIG. 2 shows a top partial cross-sectional view of the roller cage of FIG. 1;

FIG. 3 shows a partial cross-sectional view of a further embodiment of the roller cage according to the present invention;

FIG. 4 schematically shows a profiling line.

A profiling line (FIG. 4) comprises a plurality of roller cages (G), arranged in succession along a longitudinal direction (Y), which is also the feed direction of the profile (P) being machined. As is well known, roller cages are configured to progressively bend the starting steel strip around the longitudinal axis (Y), until lending it a tubular shape. The starting strip is bent by passing the strip itself between the rollers of the various cages which, by contact, progressively produce the deformation thereof. In other words, the strip slides continuously through the roller cages, becoming progressively deformed. Downstream of the roller cages (G) there is normally provided a welding device (W), which joins the abutting longitudinal edges of the starting strip.

As shown in FIG. 1, the roller cage according to the present invention comprises a support frame (F1) that entirely delimits a non-operating area (A1) which is external to the line, that is, an area in which the profile does not pass and no machining is performed on the profile. The support frame (F1) comprises, for example, two shoulders (S1,S2), or two weight-bearing structures that extend substantially in a vertical plane. The shoulders (S1,S2) are associated at the bottom with a base (D) and at the top with a cross-member structure (T). Overall, the support frame (F1) defines a rigid box-like structure that delimits the non-operating area (A1).

The cage comprises a motor (11) associated with the frame (F1) and provided with a spindle (12) protruding externally of the non-operating area (A1). The spindle (12) protrudes from the motor (11) in cantilever fashion, that is, it is supported solely by the motor (11), and has a free end that is not supported by other structural parts. A shaped roller (13) is mounted directly on the spindle (12) and arranged inside an operating area (B) of the line, i.e. the area in which the profile passes in order to undergo machining by the shaped roller (13). The operating area (B) is located substantially at the side of the frame (F1) and of the non-operating area (A1).

Thanks to the structure of the cage according to the present invention, the shaped roller (13) is cantilevered or protrudes from the outside of the support frame (F1). Furthermore, the shaped roller (13) has a free outer end (13 a) facing the outside, in the operator's view, without obstacles or other front parts. The shaped roller (13) is external to the frame (F1); in particular, it is on the outer side of the shoulder (S1), located on the side of the operating area (B), i.e. it is on the side of the shoulder (S1) that is not facing the other shoulder (S2). It is thus wholly evident that the shaped roller (13) can be accessed with considerable ease in case of need, for example for maintenance operations or disassembly and replacement operations.

Furthermore, the direct mounting of the shaped roller (13) on the spindle (12) makes it possible to avoid the use of reduction gearboxes and other transmission members. This implies a substantial reduction in equipment costs and energy losses, as well a considerable reduction in space requirements.

Advantageously, the cage according to the invention can be provided with a second motor (21) provided with a spindle (22) protruding externally of the operating area (A1). The second spindle (22), too, protrudes from the second motor (21) in cantilever fashion, or rather is supported solely by the motor (21), and has a free end that is not supported by other structural parts. A second shaped roller (23) can be mounted directly on the spindle (22) of the second motor (21). The second shaped roller (23) is also arranged inside the operating area (B) of the line. The two shaped rollers (13,23) can be arranged in a vertically opposed position, as shown in FIG. 1, or they can be offset from each other. Preferably, one is positioned above and the other below the profile being machined. The advantages already described for the first shaped roller (13) in terms of direct accessibility and ease of maintenance or replacement also apply for the second shaped roller (23). In fact, the second shaped roller (23) has a free outer end (23 a) facing the outside, in the operator's view, without obstacles or other front parts. The second shaped roller (23), too, is in fact external to the frame (F1); in particular, it is on the outer side of the shoulder (S1), located on the side of the operating area (B), i.e. it is on the side of the shoulder (S1) that is not facing the other shoulder (S2). The direct coupling of the second shaped roller (23) to its spindle (22) makes it possible to avoid the use of reduction gearboxes and other transmission members, with the advantages already described previously, without increasing the overall area occupied by the cage.

In the embodiment represented, the spindles (12,22) of the two motors (11,21) are substantially parallel to each other. Furthermore, the rotation axes of the two spindles (12,22) lie in the same vertical plane. The motors (11,21), too, are substantially parallel to each other, thus enabling the overall dimensions to be reduced. This does not preclude that, given particular constructive or positioning requirements, the two motors and the two spindles may be arranged differently from what is illustrated in FIG. 1; for example, they could be inclined.

Solely by way of example, FIG. 1 shows two shaped rollers (12,22) which define overall, on a vertical sectional plane perpendicular to the longitudinal direction (Y), an outline (C1) which surrounds the section of the profile in the same vertical plane. For example, the outline is circular in shape.

In a further possible embodiment, schematically illustrated in FIG. 3, the cage comprises a second support frame (F2), which entirely delimits a non-operating area (A2) which is external to the line. The cage further comprises two additional motors (31,41), associated with the second frame (F2), provided with a respective spindle (32,42) protruding externally of the non-operating area (A2). The spindles (32,42), too, are supported solely by the respective motor, and have a free end. A shaped roller (33,43) is mounted directly on each spindle (32,42), so as to be located inside the operating area (B) of the line.

The shaped rollers (33,43) are located outside the second frame (F2); in particular they are on the outer side of the shoulder (S1), located on the side of the operating area (B), i.e. they are on the side of the shoulder (S1) that is not facing the other shoulder (S2).

In the case of the second frame (F2) as well, the spindles (32,42) of the two motors (31,41) are substantially parallel to each other. Moreover, the rotation axes of the two spindles (32,42) lie in the same vertical plane. The motors (31,41), too, are substantially parallel to each other. This does not preclude that, given particular constructive requirements and/or requirements related to the forming or positioning process, the two motors and the two spindles may be arranged differently from what is illustrated in FIG. 3.

The shaped rollers (33,43) protruding from the second frame (F2) can be placed in a position that is horizontally opposed to a respective shaped roller (13,23) protruding from the first frame (F1). For example, as illustrated in FIG. 3, two upper shaped rollers (13,33) can be aligned along a same horizontal rotation axis. Two lower shaped rollers (23,43) can be aligned along a same horizontal rotation axis. The shaped rollers (13,23,33,43) can also be offset from each other, that is, they can be arranged with rotation axes that are not aligned with each other. In this regard, the arrangement of the shaped rollers shown in FIG. 3 serves to define, in a vertical sectional plane perpendicular to the longitudinal direction (Y), an open outline (C2), with a concavity facing upward. In particular, two upper shaped rollers (13,33) have an outer convex surface, tangent to the concave side of the outline (C2). Two lower shaped rollers (23,43) have an outer concave surface, tangent to the convex side of the outline (C2).

The use of a second assembly comprising the second carrying frame (F2) and the respective motors (31,41) and shaped rollers (33,43) makes it possible to obtain outlines of a greater extent or breadth.

It should be noted that all of the shaped rollers (13,23,33,43) are positioned in cantilever fashion relative to their carrying frame (F1,F2). All of the shaped rollers are turned towards the centre of the line, and in the absence of a profile (that is, in cases where maintenance or size changeover operations are planned), they are in the operator's view, without any obstacles or other front parts, except for the safety guards required under current legislation. As in the case of FIG. 1, it is wholly evident that each shaped roller (13,23,33,43) can be accessed with considerable ease in case of need, for example for maintenance operations or disassembly and replacement operations. Moreover, each shaped roller is directly coupled with its spindle, so that the cage overall requires neither a reduction gearbox nor any other additional transmission member.

Preferably, the position of each motor (11,21,31,41) is adjustable along a vertical direction. This is preferable in general, and in particular both in the embodiment of FIG. 1, and in the embodiment of FIG. 3. The vertical adjustment enables the position of the shaped rollers to be adapted to the thickness of the sheet and/or dimensions or conformation of the profile. The vertical adjustment of each motor can be obtained by means of guides and actuators, within the grasp of the person skilled in the art, interposed, for example, between each motor and the corresponding carrying frame (F1,F2).

Preferably, the position of one or more shaped rollers (13,23,33,43), can be adjusted along a horizontal direction. In particular, the horizontal direction of adjustment of each roller is perpendicular to the longitudinal direction (Y) of the profiling line, for example it coincides with or is parallel to the rotation axis of the roller itself. The adjustment of each shaped roller along the horizontal direction can be obtained, for example, by adjusting the position of the respective motor (11,21,31,41), or providing an adjustable coupling in an axial direction between each shaped roller (13,23,33,43) and the corresponding spindle (12,22,32,42). The horizontal adjustment of each motor (11,21,31,41) can be obtained by means of guides and actuators, within the grasp of the person skilled in the art, interposed, for example, between each motor and the corresponding carrying frame (F1,F2).

The horizontal adjustment of each shaped roller (13,23,33,43) enables the position of the shaped rollers to be adapted to the thickness of the sheet and/or dimensions or conformation of the profile. Furthermore, the horizontal adjustment of each shaped roller (13,23,33,43) makes it possible to align, along a longitudinal direction of the profiling line, the various cages arranged in succession, and to align the upper rollers with the lower rollers. In a possible configuration, the lower shaped rollers (23,43) are fixed, whereas the upper shaped rollers (13,33) are horizontally movable so as to be adapted to the profile of the lower shaped rollers.

In order to facilitate the longitudinal alignment of the various cages arranged along the profiling line, the carrying frame or frames (F1,F2) of each cage can be equipped with a horizontal adjustment means, which enables the position of each carrying frame to be adjusted along a horizontal direction perpendicular to the longitudinal direction (Y) of the profiling line. The presence of the horizontal adjustment means enables the length of the spindles to be reduced. In fact, the smaller the profile to be made is, the more each cage will be shifted towards the centre of the line, thereby reducing the distance between the centre of the profile and the spindles. This makes it possible to increase the rigidity of the spindles and the precision of the line. The horizontal adjustment means can comprise, for example, a guide interposed between the base (D) of each frame (F1,F2) and an actuator device for controlling the sliding of the carrying frame along the guide. The adjustment means is within the grasp of the person skilled in the art and will thus not be described in further detail.

The profiling line comprising a plurality of roller cages (G) according to the present invention can be equipped with an automatic device for aligning the shaped rollers (13,23,33,43) relative to the longitudinal direction (Y). Essentially, the device is configured to adjust the position of each shaped roller (13,23,33,43) along a horizontal direction perpendicular to the longitudinal direction (Y) and along a vertical direction. This adjustment could be made, for example, by horizontally and/or vertically moving each motor (11,21,31,41), in the manner already described previously, or in combination with the horizontal movement of the support frames (F1,F2). The alignment device can acquire the actual position of each shaped roller (13,23,33,43) by means of a detector of an optical type, for example by means of a laser detector.

Moreover, each roller cage (G) can be equipped with a dimensional detector (not represented) placed preferably on the exit side, configured to detect and measure certain geometric parameters of the profile exiting the cage (G), for example a radius of curvature, or the height or width of the profile relative to a horizontal plane. Each dimensional detector can be connected to the automatic alignment device, which serves to adjust the position of each shaped roller in relation to the signal received, thus optimising the forming process.

In a preferred embodiment, each motor (11,21,31,41) is a permanent-magnet brushless motor. In particular, each motor (11,21,31,41) is a motor of the torque type. As is well known, a torque motor lends itself particularly well to a direct coupling with the member to be driven in rotation, in this case a shaped roller.

The roller cage according to the present invention achieves important advantages.

The cantilevered positioning of the shaped rollers (13,23,33,43) present considerably facilitates all roller maintenance, disassembly and replacement operations, since the rollers are facing the operator without obstacles or other front parts.

Furthermore, the direct coupling between each shaped roller present and the respective spindle makes it possible to avoid the use of reduction gearboxes, joints and other transmissions which, in addition to increasing the costs of the cage, produce an appreciable reduction in the mechanical efficiency of the cage itself.

The version of the cage comprising two opposing support frames, each with its own shaped rollers, together with the possibility of adjusting the position of each shaped roller relative to the longitudinal direction of the profiling line, increases the conformations obtainable for the profile being machined. 

1. A roller cage for a profiling line, characterized in that it comprises: a support frame (F1) that entirely delimits a non-operating area (A1) which is external to the line; at least a motor (11) provided with a spindle (12) protruding externally of the non-operating area (A1); at least a shaped roller (13), mounted directly on the spindle (12) and arranged inside an operating area (B) of the line.
 2. The cage according to claim 1, wherein the spindle (12) is supported solely by the motor (11) and has a free end.
 3. The cage according to claim 1, comprising a second motor (21) provided with a spindle (22) protruding externally of the non-operating area (Al); a second roller (23), mounted directly on the spindle (22) coupled with the second motor (21) and arranged inside the operating area (B) of the line.
 4. The cage according to claim 3, wherein the spindle (22) is supported solely by the second motor (21) and has a free end.
 5. The cage according to claim 1, wherein the support frame (F1) comprises two shoulders (S1,S2) between which the non-operating area (A1) is defined, and wherein the first roller (13) and, if present, the second roller (23), are located externally of the frame (F1), that is, they are located on the side of the shoulder (S1) that is not facing the other shoulder (S2).
 6. The cage according to claim 3, wherein the spindles (12,22) of the two motors (11,21) are substantially parallel to each other.
 7. The cage according to claim 1, comprising a second support frame (F2), which entirely delimits a non-operating area (A2) external to the line; two motors (31,41) provided with a respective spindle (32,42) protruding externally of the non-operating area (A2); a shaped roller (33,43), directly mounted on each spindle (32,42) and arranged inside the operating area (B) of the line.
 8. The cage according to claim 7, wherein the spindles of the motors (32,42) are substantially parallel to each other.
 9. The cage according to claim 1, wherein the position of each motor (11,21,31,41) is adjustable along a vertical direction.
 10. The cage according to claim 1, wherein the position of at least one motor (11,21,31,41) is adjustable along a horizontal direction.
 11. The cage according to claim 1, wherein each motor (11,21,31,41) is a permanent magnet motor.
 12. The cage according to claim 1, wherein each motor (11,21,31,41) is a motor of the torque type.
 13. A profiling line comprising a plurality of roller cages (G) according to claim 1, aligned along a longitudinal direction (Y).
 14. The profiling line according to claim 13, comprising an automatic alignment device, configured to adjust the position of each shaped roller (13,23,33,43) relative to the longitudinal direction (Y).
 15. The profiling line according to claim 13, wherein each roller cage (G) comprises a dimensional detector, configured to detect one or more dimensions of the profile (P) exiting the roller cage (G), said dimensional detector being connected to the automatic alignment device. 